Micrometric particles twodimensional self-assembly during drying of liquid film

We computed the self-organisation process of a monodisperse collection of spherical micrometric particles trapped in a two-dimensional (2D) thin liquid film isothermally dried on a chemically inert substrate. The substrate is either flat or indented to create linear stripes on its surface. The numerical results are illustrated and discussed in the light of experimental ones obtained from the drying of diamond particles water based suspension ($d_{50} = 10 \mu m$) on a glass substrate. The drying of the suspension on a flat substrate leads to the formation of linear patterns and small clusters of micrometric particles distributed over the whole surface of the substrate, whereas the drying of the suspension on a indented substrate leads to the aggregation of the particles along one side of the stripe which has a higher roughness than the other side of the stripe. This is an easy experimental way to obtain colloidal selforganized patterns.Comment: 16 pages 7 figure

Theoretical approach to the masses of the elementary fermions

International audienceWe made the hypothesis that, if spacetime is composed of small hypercubes of one Planck length edge, it exists elementary wavefunctions which are equal to √ 2 exp(ix j) if it corresponds to a space dimension or equal to √ 2 exp(it) if it corresponds to a time dimension. The masses of fermions belonging to the first family of fermions are equal to integer powers of 2 (in eV/c 2) [1]. We make the hypothesis that the fermions of the 2nd and 3rd families are excited states of the fermions of the 1st family. Indeed, the fermions of the 2nd and 3rd families have masses equal to 2 n .(p 2)/2 where n is an integer [1] calculated for the first family of fermions and p is another integer. p is an integer which corresponds to the excited states of the elementary wavefunctions (the energy of the excited elementary wave functions are equal to p 2 /2; using normalized units)

Analysis of a Lennard-Jones fcc structure melting to the corresponding frozen liquid: differences between the bulk and the surface

We computed a Lennard Jones frozen liquid with a free surface using classical molecular dynamics. The structure factor curves on the free surface of this sample was calculated for different depths knowing that we have periodic boundary conditions on the other parts of the sample. The resulting structure factor curves show an horizontal shift of their first peak depending on how deep in the sample the curves are computed. We analyze our resulting curves in the light of spatial correlation functions during melting and at when the liquid is frozen. The conclusion is that near the free surface the sample is less dense than in the bulk and that the frozen liquid surface has a spatial correlation which does not differ very much from that of the bulk. This result is intrinsic to the melting of the Lennard Jones liquid and does not depend on any other parameter.Comment: 18 pages 9 figure

ITER cryostat accidental scenario: fluid dynamics analysis of Ingress of Coolant Event Accident

ITER (International Thermonuclear Experimental Reactor) is an experimental reactor aimed at demonstrating the technological and scientific feasibility of fusion technology. A future fusion power plant producing large amounts of energy power will be required to breed all of its own Tritium. ITER will demonstrate this essential concept of Tritium self-sustainment. Among the most important components of that reactor there is the cryostat that is, specifically, a large stainless steel structure surrounding the vacuum vessel and the superconducting magnets, providing a super-cool vacuum environment. The aim of this paper is to evaluate the effects caused by a suddenly rupture of one of the cryogenic lines with release of helium inside the cryostat, event known as CrICE: Ingress of Coolant Event in Cryostat. The CrICE accident scenario has been simulated by ANSYS©CFX. To the purpose, a suitable model representing a 20° sector of the overall ITER structures, vacuum vessel, magnets, thermal shield, ports and cryostat was set up and implemented, in order to characterize and define the free volume to be filled by the gas that would be released eventually as well as the air inside the bioshield. The numerical model, the geometrical characteristics and the materials properties used as input in the simulation of the accidental scenario have been presented and discussed. The results obtained indicated that the cryostat is capable to sustain the pressure and the thermal loads generated by the accident conditions. It is also worthy to remark that these results (raw outcomes) will be used for a further detailed investigation of the structural performances of cryostat itself